Two-dimensional model of elastically coupled molecular motors

A flashing ratchet model of a two-headed molecular motor in a two-dimensional potential is proposed to simulate the hand-over-hand motion of kinesins.Extensive Langevin simulations of the model are performed.We discuss the dependences of motion and efficiency on the model parameters,including the external force and the temperature.A good qualitative agreement with the expected behavior is observed.     

A feedback-controlled Brownian ratchet operated by a temperature switch

In this paper, we present a model of the Brownian motor in a feedback controlled ratchet, in which the application of the flashing potential depends on the state of the particle to be controlled. We derive an analytical expression for the velocity induced by the feedback ratchet, which is a function of several parameters, including the ratio of the two switching temperatures and the asymmetry parameter of the potential field. The motor shows a current inversion when either parameter is varied.     

甚高频高速沉积微晶硅薄膜的研究

采用甚高频化学气相沉积(VHF-PECVD)技术制备了系列微晶硅(μc-Si:H)薄膜样品,重点研究了硅烷浓度、功率密度、沉积气压和气体总流量对薄膜沉积速率和结晶状态的影响,绘制了沉积气压和功率密度双因素相图. 以0.75nm/s的高速沉积了器件质量级的微晶硅薄膜,并以该沉积速率制备出了效率为5.5%的单结微晶硅薄膜电池. 关键词： 微晶硅薄膜 高速沉积 甚高频化学气相沉积     

高气压下微晶硅薄膜的生长及微结构研究

通过射频等离子体增强化学气相沉积,在高气压条件下制备了微晶硅薄膜,并用拉曼光谱仪(Ram an)、扫描电镜(SEM)研究了微晶硅薄膜的微观结构。发现沉积速率在5Torr左右出现极大值,薄膜的晶化率随着沉积气压的升高而降低,薄膜表面的晶粒或团簇随着沉积气压的下降而增大,薄膜的粗糙度随着沉积气压的升高而降低。     

Two-dimensional model of elastically coupled molecular motors

A flashing ratchet model of a two-headed molecular motor in a two-dimensional potential is proposed to simulate the hand-over-hand motion of kinesins. Extensive Langevin simulations of the model are performed. We discuss the dependences of motion and efficiency on the model parameters, including the external force and the temperature. A good qualitative agreement with the expected behavior is observed.     

A feedback controlled Brownian ratchet operated by temperature switch

In this paper, we present a model of the Brownian motor in a feedback controlled ratchet, in which the application of the flashing potential depends on the state of the particle to be controlled. We derive an analytical expression for the velocity induced by the feedback ratchet, which is a function of several parameters, including the ratio of the two switching temperatures and the asymmetry parameter of the potential field. The motor shows a current inversion when either parameter is varied.     

SiH4/H2等离子体气相生长硅薄膜的动力学模型

在化学气相沉积微晶硅薄膜过程中,为了降低成本,必须提高生长速率,但薄膜的微观结构和光电性能则随之降低,原因是成膜先驱物在薄膜表面上的扩散长度降低了. 本文利用量子化学的反应动力学理论建立有关成膜先驱物SiH₃和H的反应平衡方程,求解薄膜生长速率和成膜先驱物的扩散长度,并找出影响生长速率与扩散长度的微观参数,发现生长速率不仅与流向衬底的SiH₃的通量密度有关,而且与H的通量密度有关;SiH₃的扩散长度与衬底温度和薄膜表面的硅氢键的形态有关,当